Answer:
Good because no need to do a long process when they get caught. Bad because it would take way too long and things could get mixed up
Step-by-step explanation:
It sounds good because as stated it would be easier to catch criminals. You wouldn't have to waste time getting DNA you already have. Bad because not only would it take a long time to get a DNA sample from EVERY american but it would leave people vulnerable if it fell into the wrong hands
Sorry that took a while hope its good